Abrasive disk support



p w. STEVER ABRASIVE DISK SUPPORT Filed March 5, 1947 INVENTOR WilliamSteuer A TTORNE Y Patented Sept. 6, 1949 PATENT I i r 4 ansoisso 1 vAnnns vn DISK SUPPORT a 7 William- Steven Philadelphia, Pa.,assignor-tm'llie "Budd Company, Philadelphia, Bat, aL-oorpome.

tion uf-liennsylvaniar v Application Marchva', 1941., ses me. 1321114:

1 The relates tosupports for abrasive discs bvja. rotatably driven'inember" or head. More particularly, inventionrelatesto abacking padtorarr disc and 'toi'neans for firn lyconnectingfsucirpadiand theabrasive disc mmgf mm a v i V Among the. objects of; the invention is-anarrangein'ent. which perrnitsioi aqnick eha-nge of abrasivediscs whiie'firnilyhqlding the same during theoperation sothat danger of a disccoming oli and?causinginjurv or other damage is eliminated or greatlyminimized".

Anothenobiect'of'the inventionis a resilient supporter backing pad foran abrasive disc which likewise permit'sfoflquick exchange in-case a padof anothersize or resiliencyis reguired or in case the previouslyused pers wdr n: out; Still another object of the" invention is a supportingheadand af backihg'pad which is inexpensive'and yet ma eump so "as towith-- stand for a long time such'roughusag-e as will occurmetaishops"vvhere "abrasive discs are W e ye a I V An obi'ectfof theinvention is also the avoidance of the'so-calledknife-type headand disccon-- nection as'it" disclosed-inapplicants Patent No; 1,928,800,Abrasive apparatus, of October 3,1983,"a type which hasbeen in extensiveuse for agre'at many years. This knife-type sup port 'is'liableto'ceuse'iniuryby the knives and the disc sometimeseauses-injuryby"fiying off when the supporting head is' suddenly stopped;

A more specific object of the-invention is the improvement oiapp'licantsdevices as disclosed in his Patents No. '2-,402;691,"Supporting head forabrasive discs, of June 25,1946, and-No 2,4 9,153; Backing pad' forabrasive discs, of Catcher 8,

With the aforesaid objects in view, the invention residesoutstandinglyinthe combination of a 'rotatably'driven supporting head and a clampingmemberfor" the abrasive discs to the. head with a resilient backing padhaving a central opening, a pluralitv or ra iall outwardlyex tendingslots or slits and an annular contact zone between head and supportingdisc outwardly of the ends oi the slots, theportions of the padseparated by the slots, being engaged by said clamping member and exerta locking effect on the clamping'm'einber' holding it firmlyin place butpermitting, nevertheless, the relatively easy removal of the clampingrnember for the exchange 'of the abrasive disc. I

'I'he'aioresaidalid'other objects and features 6:Claims wran ler);

from the embodiment illustrated in the attached;

drawing and describedhereinaiterw In the drawing?" a Figure 1 is partlya side elevation otian'd partly a radial section"through anr abrasivedisc'y'a supporting orbacking pad and-a supporting head; Figure 2 is aplan view of the backing pad Figure Ti: i'fv'jl" g Figure 3 is aperspectiveview of a disc member'- for connecting the backing mad: withthe-sup porting headia-nd j Figure dis a fragmentary-sectioncorresponding to part of Figure 1 tutsnewmg heaa, baekin g pad andabrasive disc priorto thie application orai ter the removal or theshinning-member for holding the abrasive disc.

The head it, whiehmay consist oi an alumicasting or othersuitable'metalon material,

isgenerally-a body or solid'oi revolution andhas one I endinteriorly-threaded at H for connection to a driven shaft (not shown),At the other end, the headfhas a radially relitw ardlyflaring-flangeljZ, the end face of which is recessed -at= I 3 and has an annularsupporting surface '14. An annular projection F5 suemounts the bottom ofthe recess-I53 and is provided with radially out-- wardly extendingsectors-i 5 forming one-half of a bayonet joint. Th'eothe'r haif of thebayonet joint is formed on a disc it eonsisting; preferably ofsheet'metal, having a-centr-ai opening and having the margin of "the"opening provided with sector shaped cutouts ll leavingbetween themradially inwardly projecting-sector-shaped projections 18." At one end,eaeh-projection'ls is formed with *a'naxially' outwardly directed earflange or-tongue IQ'forlimitingthe rotation of the disc 1 6 relative tothe head In when the two members arebrought into engagement with or are"disengaged from each other} It will be noted that the flat-middleportion (if the disc it rests on the surface -I 4 ot the *head' while--it s inner portijon'is dished out so; as to fit intothe recess l3 ofthe head);

Spacing discs 20 -and a backing disc 2! are connected to the "outerperipheral "portion of the disc '6 b mean 0i coun su k r et '2 Thediscsfgll and}! '"consistpreferably of vulcanized re, n ast cso any oher mate ia t at has he oughness and resilienc e i e fe bac ing di c andr the purposes oi the i vention which-are nowggin g' tg'be described.

When not in use, the discs 12!! and'gl are subtantially plane and th iinne rc tio s' u ounding a i entr icpe g mende in them of the inventionwill be more 'easiiy understood .55 are radially -js l 1 i g at 2.1."These siits g extend from the opening radially outwardly to about theregion where the discs 20, 2| contact the metal disc l6. The slots 24leave between them stiff but somewhat resilient portions or tongues 25,the stifiness and resiliency depending on the material and the thicknessof the discs 20, 2| and also on the number of slots. To insuresufficient flexibility of the tongues 25, at least five about equallyspaced slits 24 are necessary, while the maximum number of slits iseight to twelve. About eight slits 24, as illustrated, is considered theoptimum.

After the discs I6, 26 and 2| 'areconnected with the head, an abrasivedisc 26 is placed on the disc 2| and hereupon a mushroom-like screw 21is screwed with its shank 28 into the matingly screw threaded opening 29of the head 16. 28 and 29 are multi-threaded with a high pitch so ,that'a relatively small rotative relative movement between screw 21 and headill will draw the two together. The head-V36 of the screw 21 isapproximately lentil-shaped having a spherical outer face 3! and .aconical inner face 32. The inclination of the conical face 32 isaboutequal to the inclinationof the dished portion of disc I6. I

When the screw 21 is tightened, its conical face 32 bends the centralportion of the abrasive disc 26 and the underlying tongues 25 of thediscs 20, 2| downwardly. On account of the resiliency of the discs 20,2|, the pressure against the clamping member 21 is maintained during theoperation of the device, thereby exerting a locking action andefiectively preventing the member 21 from coming loose.

Of course, the construction of the screw 26 and the direction ofrotation of the head In with its associatedparts'will be selected sothat disc 26 will tend to tighten the screw Zlrather than loosen it. I 1

While the wscrewZ'l may be initially tightened by holding the head I!)with one hand or in a fixture and pressing the palm of the other handagainst the spherical surface 36 of the screw, the final tightening maybe effected by gripping the outer peripheral portion of the disc26 androtating it relative to the head during which motion the member 21 willbe taken along by the abrasive disc 26. The removal of the member 26 maybe carried out in the reverse sequence of operations, that is, first thescrew 21 is loosened by holding the disc 26 and; head l and rotating thesame relative to each other and by-then gripping the member 21 with-onehand for completely removing it so as totake ofi the disc 26 and inserta new one.

Merely in passing, it needs to be said that after the removal of themember 21 and thedisc 26 backing pad I6, 26, 2| can easily be taken off,reinserted or exchanged on account of the bayonet connection l, l1, l8,l9.- So asto facilitate the holding of the head 10, its inner end may besquare or hexagonal or a middle portion thereof may be flattened off at33 on both sides. 1 I

While but one embodiment of the invention is shown and described,modifications and adaptations of the invention will occur to thoseskilled in the art, and protection is sought for the invention asexpressed by the language and the spirit of the attached claims.

What is claimed is:

1. Resiliently flexible backingdisc for connec-. tion to a drivenrotating head and for supporting an abrasive disc, said backing dischaving a thickness and a resiliency suificient for sustain" ing thepressure exerted on an abrasive disc supported by it during the use ofsuch abrasive disc, said backing disc surrounding a central opening andmore than five radial slots extending from the opening part way towardthe outer circumierence of the disc leaving between them tongues thatare flexible in axial direction.

2. Support for abrasive means comprising a flexible disc and a seconddisc of smaller diameter, a connection between the second disc near itsperiphery and a concentric annular portion of said flexible disc, saidsecond disc being adapted for connection to a rotatably driven shaft,said flexible disc having a central opening and a plurality of slitsextending radially from said opening at least part way toward thconnection between the two discs, the central portion of said seconddisc being dished away from the plane of said flexible disc so as topermit the flexing of the central portions of the flexible'discseparated from each other by said slits. i

3. Support for abrasive means comprising a plurality of flexible discsand asubstantially rigid disc of smaller diameter than the largest oneof said flexible discs, said rigid discbeing connected near itsperiphery to said flexible discs and adapted for connection to arotatably driven- I shaft, said flexible discs having a central openingand a plurality of slits extending at leastpart way toward theconnection between the two types of discs, the central portion of saidrigid disc being spaced from the plane of the nearest one of saidflexible discs so as to permit the flexing of th central portions of theflexible discs separated from each other by said slits.

4. Backing disc for abrasive means comprising a substantially planeflexible disc provided with a central opening and slits extendingradially outwardly from said opening part way toward the periphery ofthe disc to form; resilient tongues between said slits, a second disc ofsmaller diam-. eter than said first disc secured concentrically to saidfirst disc between the central opening and the periphery of the latterand having at least its central portion spaced from the central portionof said first disc, said second disc having its central portion providedwith one member of a joint of the type having two, members to be engagedwith and released from each other by relative rotative and axialmovement, the-other member of such joint being provided on a rotatablydriven member, the resilient tongues formed on said flexible discbetween said slits serving as resilient supports for the central portionof an abrasive disc and for a retaining member therefor adapted forremovable connection withsaid driven member.

5. In combination; a backing disc, a'supporting head adapted on one sidefor connection to a rotating shaft and onthe other side provided with acentral recess, means for connecting said head to the backing disc andwith a central removable clamping member for holding an abrasive disc,said backing disc having a, central opening and slots extending radiallyoutwardly from said opening part way toward its outer periphery, saidhead and said backing disc being formed for firm contact with each otherin an annular region outwardly spaced from said opening, said clampingmember engaging anabrasive disc and the central portion of said backingdisc inside of said annular region so as to flex the portions of thebacking disc between said slots'and thereby firmly retaining saidholding means and the REFERENCES CITED abrasive disc The followinreferen at f d th 6. An abrasive holder and support comprising ii] ces eo recor m e a supporting head, a resilient plate having a cen- 0 15 tralopening and a plurality of centrally located 5 UNITED STATES PATENTSslits forming between them resilient tongues, an abrasive-holding disc,and screw means for i ggg gg fi Nov if clamping said resilient plate anddisc in super- 127241742 1929 posed relation to said rotatable headwhile re- 2402691 Stever 1946 siliently stressing said tongues. l

WILLIAM STEVER. 2,409,163 Stever Oct. 8, 1946

